ArcGIS Pro

Sun Shadow Volume

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Summary

Creates closed volumes that model shadows cast by each feature using sunlight for a given date and time.

Usage

All input features should reside in the same locale, as relative sun position calculations are based on the position of the first feature in the first feature class.

Shadows modeling sunrise and sunset conditions can be made by providing only a date in the Start Date and Time and End Date and Time parameters, respectively. Shadow volumes will not be produced if the sun is not visible for a given date and time or if the relative position of the sun is at a vertical angle of 90 degrees from the input features.

Shadows are modeled as closed multipatches created by extruding the input features in the direction of sunlight. Light rays are considered to be parallel and travel in the direction calculated for the relative position of the sun. Each shadow volume starts and ends at a vertical plane that is perpendicular to the
horizontal projection of the sun's rays.

The following fields will be attributed to the shadow volume features:

SOURCE—Name of the feature class casting the shadow volume.

SOURCE_ID—Unique ID of the feature casting the shadow volume.

DATE_TIME—Local date and time used to calculate sun position.

AZIMUTH—Angle in degrees between true north and the perpendicular projection of the sun's relative position down to the earth's horizon. Values range from 0 to 360.

VERT_ANGLE—Angle in degrees between the earth's horizon and the sun's relative position where the horizon defines 0 degrees and 90 degrees is directly above.

Note:

Typically, each shadow volume would appear to hug, or be cast tightly against, its originating feature. If a shadow could not be generated in this manner, it will be created from the boundary of the feature's outer extent. When at least one shadow is created this way, a field named HUGS_FEATR is included to indicate which shadows hug their corresponding features.